My experiments with volcanoes

by Thomas Augustus Jaggar

I was pleased when the U.S. Naval Observatory invited me to go to Niuafoou in 1930 as the geologist on an expedition going to study the total eclipse of the sun. The expedition, under Captain C. H. C. Keppler, used the Naval Station at Samoa as a base. Mrs. Jaggar accompanied me as far as Pago Pago and made trips to Western Samoa, Fiji, and the Tonga Islands. With other wives of expedition members, she was allowed to make a short visit to Tin Can Island at the time of the eclipse in October. Spending some time in Samoa, she listened to the Congressional hearings under Senator Hiram Bingham, which were to investigate civil versus naval government. We were delighted to find our old friend Captain Lincoln, of Tokyo earthquake relief, in command of the Navy at Samoa, and I also renewed acquaintance with the pilot of my companion plane in the Molokai forced landing of 1924, Lieutenant Bill Sinton, and his family, whom we were to meet again in Honolulu. Prominent on Captain Keppler’s staff was Lieutenant-Commander Kellers, physician and naturalist, whose enterprise on the Niuafoou expedition, like mine, dealt with sciences other than astronomy.

From the sea, Niuafoou looks like a hat in shape. It is about five miles in diameter with eleven villages, mostly along the eastern shores, and at that time had a population of about a thousand people. In the center is a circular lake, bordered by cliffs, and much like Crater Lake in Oregon. Standing about seventy feet above sea level and 250 feet deep, it has slightly brackish water. The naval camp was established at Angaha on the north side of the island, and here a new village housed the refugees from Futu to the northwest, destroyed in 1929 by an aa lava flow. This flow came from erupting cracks trending north and south, along the west side of the ring ridge around the crater lake. These lava flows had been liquid pahoehoe at the source; had poured into the sea in many places; and had made striking tree molds around coconut palms, which were left as stone trees when the wood burned and the liquid lava lowered. The western source crack extends to the south end of the island and has accounted for most of the earlier eruptions known to history. Futu had been the only western settlement left.

Angaha came nearest to being a harbor, but was really on an open roadstead, with a rocky boat landing and copra chute below the village which stood on a cliff above.

Copra, the only commercial product, is bought and warehoused by two Australian firms. The two grown sons of the manager of one assisted me in tramping and photographing all over the island. The landing at Angaha brought about the name Tin Can Island, for the visiting steamers stopped a mile off shore and incoming mail, soldered into large biscuit tins by the steamship engineer, was lowered into the sea, tied together. The tins were towed in by the village policeman. Outgoing mail was carried out in paper packages tied on top of sticks and held aloft by hardy swimmers with hau wood poles, which they held under their arms as floats. A short time after our trip a shark got a swimmer, and canoes were adopted.

Thanks to the infrequent visits of vessels, the natives were unspoiled, splendid specimens of the Polynesian race. The laws of Tonga required every youth to cultivate an area of coconut trees and vegetables, and the island was traversed by lovely trails. The houses and churches were exquisite arched structures with thatched roofs, the beams tied with coconut-fiber cords. There were native ministers, and the choirs were superb. Services often started at 4 A.M.

My jobs were to take photographs with three cameras and make a geological map. Northeast of the crater lake is a cluster of sand hills, relics of an unusual explosive eruption in 1878, another Hawaiian eruption date. This eruption was confined to one side of the crater and came up the wall crack, between the encircling cliff and the top of the lava plug under the lake. Its description is very reminiscent of the Kilauea steamblasts of 1924.

We found a remarkable inhabitant of the sand in the malau bird, a small partridge with big feet, with which it dug a deep hole in the sand for its large egg which was then covered up. The sun’s heat did the rest, with the warm sand acting as incubator. The young bird scratched its way to freedom and flight without aid from its mother. Another item of Dr. Kellers’ natural history was the flying fox, a giant bat with a high singing note and odoriferous rookeries in the tops of trees. It had a heavy flight like an eagle’s. A third item was the tiny black crab, the size of a ten-cent piece, which lived in the midst of limey flats at one side of the lake, where there were crusts that suggested calcareous algae. The little black crabs, which lived by thousands in the midst of the crust, resembled compact spiders.

An artificial feature of great convenience was a trail following the top of the ring ridge, all around the crater. The Quensell boys had a rowboat on the lake, and Dr. Kellers and I were guided by them to all parts of the island, making the acquaintance of the people in the villages along the eastern trade-wind shore. Just as in Hawaii, the trade wind is a controlling feature; and the surf erodes cliffs on the east, whereas beaches are more common along the lava flows of the western strand line. These are sheltered from wind but are remote from habitations. The entire island is made of lava and ash deposits, and is evidently the top of a volcano cone extending far below sea level. The lava activity, as shown by the arrangement of the old and new source cracks, depends on concentric cracking around the caldera, which makes concentric rifts, rather than the long radial ones found in Hawaii. The crack along the west side—which had vented the succession of flows from south to north, ending with the Futu flow of 1929—indicated that the next flow might threaten Angaha. This is just what happened during the next decade, forcing the island population to be evacuated.

My geology photographs and pictures of people, ships, and dwellings were developed in a darkroom tent, which I set up in a copra shed, so as to keep the development of negatives abreast of the exposures. Copra bugs crawling over me in the dark and getting into developer added excitement, and the eternal smell of copra began to tinge my dreams.

The routine of our work was broken by two good fights, a fist fight between a Filipino steward and a sailor, and a knock-down and drag-out between two native women of Angaha. The real fun was the row between the two women. A younger woman who was a loose, shrill character, disliked by the villagers and the sailors, attempted to attack an older woman who was a big husky dame. There was screaming and hair pulling and fisticuffs, while the Navy men stood around and cheered them on. The younger woman made most of the noise, while the older woman laughed and ripped off the other’s clothes. Finally the young woman, in tears and with clothing in tatters, retreated and disappeared.